1. Field of the Invention
The present invention relates to a syringe device and a syringe plunger, and particularly, to a syringe device and a syringe plunger allowing the operation of supplying and suctioning a fluid to be performed with a single hand.
2. Description of the Related Art
In recent years, since invasion to a patient is small compared to surgery in which a laparotomy, a thoracotomy, or the like, is performed, endoscopic surgery using endoscopes (hard endoscopes), such as a laparoscope, has been widely performed. In endoscopic surgery, a plurality of holes are made in a patient's body wall, an endoscope is inserted into a body cavity from one hole of these, and a treatment tool is inserted into the body cavity from another hole. Then, treatment of a living body tissue is performed with the treatment tool while observing the living body tissue within the body cavity with the endoscope.
Generally, in endoscopic surgery, one or a plurality of treatment tools are used simultaneously with the endoscope. Therefore, since it is difficult for one surgeon to simultaneously operate the endoscope and the plurality of treatment tools, for example, a task, such as operating a treatment tool that the surgeon holds with his/her hands while making an assistant called an endoscopic technician operate the endoscope is normally performed.
Additionally, in endoscopic surgery, an overtube called a trocar, or the like is used. The overtube consists of a cylindrical body inserted into a body wall, and is a guide instrument for introducing instruments, such as the endoscope and a treatment tool, into the body cavity.
Meanwhile, a distal end of an insertion part of the endoscope is provided with an observation window, and observation within the body cavity is performed via the observation window. Therefore, although it is always necessary to keep the observation window clean, foreign matter (mucus, fats and oils, tissue pieces, or the like) may adhere to the distal end of the insertion part of the endoscope introduced into the body cavity via the overtube. In this case, since an image of a site to be treated and the treatment tool becomes unclear, operations such as a surgeon first extracting the insertion part of the endoscope from the overtube and then wiping the observation window are required. Therefore, surgery time may be lengthened or a surgeon may miss a site to be treated, which causes degradation in surgical efficiency.
Additionally, there are also many situations where foreign matter adheres to the inside of the overtube, and even if the observation window is cleaned after the insertion part of the endoscope is first extracted from the overtube, the observation window may become dirty when the insertion part of the endoscope is installed again inside the overtube.
In contrast, a syringe device being connected to the overtube, and cleaning water being supplied to the observation window of the insertion part of the endoscope, using a fluid passage disposed in the overtube may be considered. In this case, since a visual field becomes unclear if cleaning water remains in the observation window, it is desirable to suction and remove the cleaning water (remaining water) that remains on the observation window after the cleaning water is supplied to the observation window.
However, usual syringe devices have an outer tube having a nozzle of which a distal end consists of a tube, a pipe, or the like, and an inner tube inserted into the outer tube, a piston part is provided at a distal end of this inner tube, and the piston part is made to slide along an inner surface of the outer tube by performing a push/pull operation of the inner tube with respect to the outer tube. For this reason, in a case where the inner tube is pushed into the outer tube for fluid supply, a single hand operation is possible. However, in a case where the inner tube is pulled out from the outer tube for fluid suction, an operation using both hands needs to be performed, and that operation becomes troublesome.
Meanwhile, JP1997-512727A (JP-H09-512727A) discloses a syringe device (injector) adapted to allow supplying and suctioning a fluid to be performed with a single hand. This syringe device includes a syringe body (barrel), a plunger body (a cylinder for plunger driving) that is slidable inside the syringe body, and a plunger rod inserted into the plunger body. If the plunger rod is pushed and operated, a plunger (elastic body) arranged at a distal end of the plunger body is elastically deformed due to contact with the plunger rod, and if the pushing operation of the plunger rod is released, the plunger returns to its original position. In this case, since a negative pressure is generated within the syringe body, it is possible to perform a suction operation with a single hand, using that negative pressure.